Q. How do I shorten an interior door to clear a floor register?
A. Lay a sheet of cardboard or plywood on the floor that is the same height (or higher) than the floor register you need to overcome. Apply a strip of painter’s masking tape along the edge of the door. Position a pencil on the cardboard and trace a straight line over the tape to indicate where to cut, clearing the surface of the floor register by at least 1/8in. Remove the hinge pins to remove the door. Use a blanket to cover your work bench or sawhorses to protect the door finish. Rest the door on the sawhorses and clamp securely. Use a circular saw with a thin-kerf blade to cut along the pencil line. It may help to clamp a straight-edge or use the saw’s rip guide to ensure a straight cut. The masking tape will protect the finish and reduce splintering when you cut. Sand the cut edge with a sanding block. Hang the door and put the hinge pins back in place.